US Treasuries are the collateral that lubricates the world’s financial market plumbing. The bonds underpin repo markets, prime brokerage, securities lending and derivatives trading.

The market’s size, depth and liquidity give it the status of TINA: There Is No Alternative. But the US Treasury debt pile is growing and the plumbing is starting to creak. As alternative sources of collateral begin to emerge, can TINA become TIA?

Ten years ago, despite capital controls, the Chinese renminbi joined the